ORLANDO – This May, the hallowed term "dementia" is supposed to be tossed onto the scrapheap of discarded psychiatric nomenclature, replaced by "major neurocognitive disorder."
When the DSM-5 was released in May 2013, the American Psychiatric Association gave a year’s grace period for the world to absorb the changes before they take effect. "Dementia" was replaced in the DSM-5 because the term was deemed stigmatizing; the rough translation from the Latin roots is "loss of mind." Acknowledging that old habits die hard, however, the DSM-5 also states that use of the term is not precluded "where that term is standard."
The old DSM-IV category of delirium, dementia, and amnestic and other cognitive disorders has been replaced in the DSM-5 by the neurocognitive disorders category. Major or mild neurocognitive disorder from Alzheimer’s disease is included under this new category. At the annual meeting of the American Association for Geriatric Psychiatry, Dr. W. Vaughn McCall and Dr. George T. Grossberg highlighted the changes.
"Major neurocognitive disorder" is a syndrome, which includes what was formerly known as dementia. The distinction between it and the new "mild neurocognitive disorder," previously known as mild cognitive impairment or MCI, is necessarily somewhat arbitrary. Major neurocognitive disorder requires "significant" cognitive decline in one or more cognitive domains as noted by the patient, family member, or clinician along with objective evidence of "substantial" impaired cognition compared to normative test values.
"In contrast, the requirements for mild neurocognitive disorder are ‘mild’ cognitive decline observed by patient, family member, or clinician and ‘modest’ impairment on testing, explained Dr. McCall, professor of psychiatry and health behavior at the Medical College of Georgia, Augusta.
Dr. Grossberg offered two practical tips in drawing the distinction between major and mild neurocognitive disorder. One is whether the cognitive deficits are sufficiently limited in scope that the patient is still able to function independently in everyday activities.
"If they’re not, I’m moving from [mild] to major," said Dr. Grossberg, professor of psychiatry, neurobiology, and internal medicine at Saint Louis University.
Also, if neuropsychologic testing focusing on memory is performed, Dr. Grossberg wants to see at least a one standard deviation below the expected age- and education-adjusted norms before calling it objective evidence of "substantial" impaired cognition rising to the level of major neurocognitive disorder.
Since major neurocognitive disorder is a syndrome, Dr. McCall said, it’s important to try to specify its nature. For the condition to qualify as major neurocognitive disorder from Alzheimer’s disease under the DSM-5, the impairment in cognition must be insidious in onset and gradual in progression. The patient must either have a causative Alzheimer’s disease mutation, which is present in less than 1% of all cases of the disease, or else the patient must meet three criteria: a decline in memory and learning, plus at least one additional cognitive domain; a steady decline without extended plateaus; and no evidence of mixed etiology involving cardiovascular disease or other disorders.
"There’s no requirement that memory impairment be the first affected domain. That’s a bit of a change," the psychiatrist noted.
The office-based assessment of neurocognitive disorders as recommended in the DSM-5 includes a careful history and an objective measure of cognitive function such as the Montreal Cognitive Assessment, the Saint Louis University Mental Status Evaluation, and the Mini-Mental State Examination. The patient’s ability to perform activities of daily living should be objectively evaluated, as by the Katz Index of Activities of Daily Living scale or the Barthel Index. A screening neurologic exam should be part of the work-up; this can be performed by a primary care physician or a neurologist if the psychiatrist prefers. Since major neurocognitive disorder is a syndrome, the DSM-5 does not require imaging via MRI or CT, although both Dr. McCall and Dr. Grossberg said this was a controversial issue during the creation of the DSM-5, and they recommend one-time baseline neuroimaging in order to rule out a tumor, old stroke, or frontotemporal atrophy.
Laboratory tests deemed an essential part of the work-up are a complete metabolic profile, thyroid stimulating hormone, a complete blood count, urinalysis, and folate.
In addition, Dr. Grossberg said, many memory clinics now routinely include measurements of vitamin D level, homocysteine, and C-reactive protein in the work-up.
"Vitamin D deficiency is extremely common. We’re finding in St. Louis – and I don’t think it’s a whole lot different among the elderly even in Florida, where there’s a lot of sun – that people are afraid of the sun now so they put on a whole lot of sunscreen, preventing vitamin D absorption. We check vitamin D levels routinely in our clinic, and maybe two out of every three older adults we test are low in vitamin D. More and more research shows that deficiency may be related to depression and may also have an effect on cognition. It’s something that’s easily remediable. We give 50,000 IU orally per week for 8 weeks, then a maintenance dose of 1,000-2,000 IU/day," Dr. Grossman said.